stevenKm (Mechanical) (OP)
3 Apr 12 16:59
Hello everyone. First, a disclaimer: I am not a certified mechanical engineer nor HVAC technician. However I am a mechanically inclined facilities manager. I've been reading through the forums and this seems like a friendly group with a wealth of knowledge.
Here's the problem: I've got a chilled water valve that is not closing and I've been having to control temps by manually shutting or sometimes just cracking open the shut off valve on the cold water supply line. I have had multiple certified HVAC technicians come out to trouble shoot the problem but none of them can seem to fix it. I've been told that the valve is functioning properly and that it "MAY" be a control issue. The most recent service call seemed to temporarily fix the problem. The technician said he reset the controller. However, now the problem has reappeared and the cold water valve isn't closing again.
The system is less than 5 years old. I was also told that my predecessor had to have the valve or actuator replaced in the past.
I don't know how much faith I put in the local technicians to solve this and I'm looking for ways to at least make sure that they are correctly identifying the issues.
I have attached photos of the chilled water actuator and valve.
Here are my questions:
1. What is the best way to test the proper functioning of both the valve and the actuator?
2. If it is indeed a control issue, how likely is it that "resetting" the controller would have worked temporarily?
3. If this is indeed the second broken valve or actuator in less than 5 years, what might be causing this premature failure?
Any help or advice is greatly appreciated. Thank you!